I know what you mean re: the smooth parts. It may simply be aesthetics, but compared to my Norinco, my M1A (Loaded) simply *feels* better. Smooth metal surfaces with a vastly better finish, much smoother bolt travel, and amore solid, dense walnut stock that's contoured to fill my hands better and simply feels a whole lot better when I'm holding it. Is that worth $2K when you could buy 3-4 Norincos for the same money?
On the other hand, the Norinco I own has been severely upgraded. Douglas air-gauged NM barrel, USGI parts wherever possible, and even a hooded match rear aperture. When the dust settled, it ended up costing $1,500. It still doesn't fit or feel as good as the M1A -- but it's the more accurate of the two.
All I know for certain is that these two rifles together have taught me that life is too short to spend it shooting stock Norincos, at least the ones I've owned before. Have been there, done that, and have seen the difference on targets that quality makes...